Exploring the morphological characteristics of the adult coccyx: a computed tomographic study with clinical...

The coccyx exhibits significant anatomical variation in its morphology, vertebral number, and joint fusion patterns. These variations can influence the development of coccygodynia, a common yet often underdiagnosed cause of chronic lower back pain. Understanding coccygeal anatomy is essential for accurate diagnosis and effective clinical management.

A retrospective analysis was performed on 107 lumbosacral CT scans (63 males and 44 females; age range: 18-84 years). The study evaluated the number of coccygeal segments, coccyx type (as per established classification), presence of sacrococcygeal and intercoccygeal fusion, and the occurrence of coccygeal spicules.

Type I coccyx was the most frequently observed (n = 43), followed by type II (n = 37), type III (n = 21), and type IV (n = 6). The majority of subjects had four coccygeal vertebrae (n = 53), followed by five (n = 39), three (n = 12), and two (n = 3). Sacrococcygeal fusion (partial or complete) was present in 47 subjects (43.66%), while 60 subjects (56.33%) showed no evidence of fusion. Intercoccygeal fusion affecting one or more segments was noted in 95 individuals, with only 12 showing no such fusion. Coccygeal spicules were identified in 10 subjects.

These findings underline the substantial morphological diversity of the coccyx and reaffirm the importance of high-resolution imaging in assessing coccygeal anomalies and planning interventions for conditions such as coccydynia.